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What’s the first thing you think of when you hear “latent semantic indexing”?

The answer is probably, “uh, what?”

It’s okay if that’s the case. Fortunately, it’s a simple concept to get a grip of (scary-sounding technical language aside). In fact, you’re probably familiar with the concept, even if you’ve never heard of the term.

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What Is Latent Semantic Indexing?

Let’s start with the technical explanation first. According to SEMPO, latent semantic indexing “uses word associations to help search engines know more accurately what a page is about.” It’s essentially an algorithmic principle built into search engines to process synonyms and understand topical relationships between words.

That’s about as much as we marketers need to know. We could go more in-depth. However, we don’t want anyone to feel like this:

Why Is LSI Necessary?

Say you’re talking to a friend about marketing. You start discussing how content calendars work. Throughout the discussion, you also use the term editorial calendar interchangeably.

Since you’re intelligent human beings, you can understand that when someone says “content calendar,” they might also mean “editorial calendar.” If one of you had mentioned CoSchedule, you might understand that’s a content calendar solution. The same would apply if someone said they use a “printable calendar template.”

You know those are all semantically related terms, connected to the same topic.

Search engines aren’t humans. They can’t naturally process language like you and your friend in the example above.

That’s where latent semantic indexing comes in. It’s what helps them attempt to interpret relationships approximately the same way real people would. By connecting related terms and interpreting the search intent behind them, search engines can offer up results that more closely match what people are looking for (even if the search terms they use aren’t exactly the same keywords used on the web page).

What Are LSI Keywords?

These are the actual terms and phrases that are semantically related to one another. This means words that refer to the same topic (or drill deeper within a topic). For example, “Tesla Motors” is semantically related to “electric cars,” since the company makes electric vehicles.

It may be easiest to think of LSI keywords as secondary keyword phrases that relate to your primary keyword. For example, let’s say you’re writing a piece of content about electric cars. “Electric cars” might be your primary keyword. Then, you might reference different models of electric vehicles (like the Tesla Model S, the Chevy Spark, and so on).

Benefits Of LSI-Driven Keyword Research

This is where LSI starts to matter for you, the intrepid content marketer.

Incorporating LSI keywords can help your content rank for a wider variety of search terms. This means more visibility in search results, and more traffic back to your blog or website. They can also help you create content that more thoroughly satisfies what searchers are looking for.

It’s important to remember that LSI keywords aren’t just limited to synonyms for your primary keyword.

For example, a post targeting “classic Chevy motors” might also rank for “classic Chevrolet engines” because Chevy and Chevrolet are the same, as are motors and engines). If you were to include sections for engines from specific Chevy models, you might rank for those terms as well.

5 Ways To Find LSI Keywords

You need to know how to find LSI keywords before you can use them. Fortunately, this isn’t difficult. You can even use a lot of the keyword research tools you’re probably already familiar with.

1. Use The LSI Keyword Generator

One quick tactic is to use a tool called the LSI Keyword Generator. Just type in a keyword or topic, and it’ll instantly generate a list of related terms. Best of all, it’s completely free.

2. Look At Related Searches In Google

This tactic is great because it leverages actual search terms. These are also terms Google can clearly see are related. Just try searching a given keyword, then scroll down to the bottom of the page. You now have eight different LSI variations to inspire your keyword research.

This will give you a good idea of what your own content needs to address the topic.

Step 2: Narrow Your Options Through Process Of Elimination

Start by weeding out terms that obviously don’t fit. These are terms that aren’t quite directly related to the topic of your post.

Ideal LSI keywords should essentially fit underneath your primary keyword. They need to help further explain your topic in deeper detail. They should not be distinctly different topics.

For example, if you were writing a post about “Chevy engine maintenance,” you wouldn’t want to load your post with pictures of “classic Chevy cars”. In this case, keywords that go deeper into the specifics of Chevy engine maintenance would make better choices. In this case, you’d eliminate anything that isn’t directly related to some facet of working on Chevrolet engines.

Step 3: Choose The Best Options From What’s Left

Next, copy and paste what’s left into the keyword tool of your choice. Pick terms that have a decent amount of search volume (but not more than your primary keyword). If you uncover keywords that get searched more than your main topic, that may be a sign you should be targeting that term instead. It’s also important to make sure your selected LSI keywords directly fit your topic.

How To Implement LSI Keywords Into Your Content

Once you’ve selected your LSI keywords, it’s time to determine where they’ll go in your post.

Start by identifying your blog post topic and a good primary keyword to focus on. Then, identify other keywords that relate to sub-points beneath that topic.

For example, if you were writing a post about the different styles of restaurants (this is really generic, we know, but it’s just an example), your main keyword might be something like, “styles of restaurants.” Then, each LSI keyword might be a specific style of restaurant.

For another example, “pepperoni pizza” and “cheese pizza” are related terms (both are different types of pizza). If a web page were all about pizza, and pizza was the primary keyword, then specific types of pizza could be used as LSI terms. Then, the page could have a sub-section for each type of pizza.

LSI Keywords Help Google And People Understand Your Content

LSI keywords aren’t just important for search engines.

Readers want to be able to skim and see that your post covers deeper details about the topic they’re searching. This makes incorporating LSI terms particularly effective when included in subheadings, where they’re easy for readers to pick out, and are given greater weight to search engines.

Ultimately, the goal is to create a post that targets a complete (yet focused) topic, rather than just dumping a keyword essay onto a page and hoping it will rank. This approach works best if your secondary keywords relate to specific details about your main topic.

Avoid Blending Unrelated Topics

Let’s say your main keyword is “car maintenance”. However, you also notice “motorcycle maintenance” also gets a lot of search volume. You then decide to write a post titled something like, “10 Awesome Car & Motorcycle Maintenance Tips.”

Something like this might work. However, it’s more likely that searchers looking for “car maintenance” and “motorcycle maintenance” are really only looking for one or the other. In this case, you’d better serve your readers by writing one post on each topic. Then, you’d have two super-focused posts on your blog that nail the specific needs of each audience.

Pro Tip: It’s best to choose LSI keywords that drill down into one topic. Not two keywords that address two different topics.

Avoid Diluting Your Keyword Targeting

It’s important to remember your content should only target one primary keyword.

For example, if you’re writing a blog post about “easy car maintenance,” you probably don’t need to add a section about “the history of cars.” Even if both terms get a high search traffic, the history of automobiles isn’t directly related to car maintenance. It’d be better to focus on keywords related to the different car maintenance tasks your post would cover, like: engine maintenance, tire maintenance, and so forth (note: this is a strictly hypothetical example).

The key takeaway here is to make sure your posts stay focused in on one topic (and that you choose LSI keywords that drill deeper into that one topic).

Avoid Keyword Stuffing

Use LSI keywords judiciously. This means incorporating those terms tastefully to make your content more complete. Avoid shoehorning terminology into your content merely for the sake of it. If there isn’t an editorial purpose for incorporating a section around a given term, then leave it out.

Have Questions About Latent Semantic Indexing?

By now, you should understand what LSI means. You also know how it impacts best practices for keyword research. However, this is a complex topic. We’re sure you probably have some questions, and if so, we want to hear them. Drop us a line below and help us get the conversation started.

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Ben is the Blog Manager at CoSchedule. His specialties include blogging, content strategy, SEO, social media, email marketing, and more. When he's not hard at work helping people create better content, he can be found playing bass guitar, drinking fine beer, and chasing his dog around the house.

It seems like these LSI techniques completely align with just writing good content. Just keep all of your sub-points related to the subject of the post (i.e. your keyword) and you should be good to go. Am I missing something?

Ben Sailer

You’re absolutely right that understanding how latent semantic indexing works really just goes hand in hand with writing good, comprehensive content. However, but there’s value in understanding how that content is interpreted by search engines, and how to intentionally target the best terms to incorporate in your writing (especially in cases where those terms aren’t obvious).

LSI sounds complex in theory, but once you know how it works, incorporating it into your keyword research and content creation is pretty simple.

Thanks for sharing article on LSI and make it look simple to understand. LSI will definitely help natural and good written content to rank high.

Also, as you mentioned that while writing an article, one must focus on primary keyword. This is also very essential as the article content will tell Google that post is focussed on a keyword and will eventually rank high.